U.S. patent application number 10/004119 was filed with the patent office on 2002-09-12 for heavy oil hydrocracking process with multimetallic liquid catalyst in slurry bed.
This patent application is currently assigned to PetroChina Company Limited/University of Petroleum (East China). Invention is credited to Deng, Wenan, Liang, Shichang, Liu, Chenguang, Liu, Dong, Ma, An, Men, Cungui, Meng, Chunxu, Mu, Baoquan, Que, Guohe, Shi, Bin, Wang, Zongxian, Zhou, Jiashun.
Application Number | 20020125172 10/004119 |
Document ID | / |
Family ID | 4590277 |
Filed Date | 2002-09-12 |
United States Patent
Application |
20020125172 |
Kind Code |
A1 |
Que, Guohe ; et al. |
September 12, 2002 |
Heavy oil hydrocracking process with multimetallic liquid catalyst
in slurry bed
Abstract
The invention relates to a new and improved heavy oil
hydrocracking process using a multimetallic liquid catalyst in a
slurry-bed reactor, particularly an improvement of lightweight
treatment of heavy oil in the petroleum processing technology.
According to the present invention, a slurry-bed hydrocracking
reactor and a highly dispersed multimetallic liquid catalyst are
mainly applied during the process. A fixed-bed hydrotreating
reactor is also used on line to enhance lightweight oil yield from
heavy oil under normal pressure.
Inventors: |
Que, Guohe; (Dongying City,
CN) ; Men, Cungui; (Dongying City, CN) ; Meng,
Chunxu; (Dongying City, CN) ; Ma, An;
(Dongying City, CN) ; Zhou, Jiashun; (Dongying
City, CN) ; Deng, Wenan; (Dongying City, CN) ;
Wang, Zongxian; (Dongying City, CN) ; Mu,
Baoquan; (Dongying City, CN) ; Liu, Chenguang;
( Dongying City, CN) ; Liu, Dong; (Dongying City,
CN) ; Liang, Shichang; (Dongying City, CN) ;
Shi, Bin; (Dongying City, CN) |
Correspondence
Address: |
Andover-IP-Law
44 Park Street, Suite 300
Andover
MA
01810
US
|
Assignee: |
PetroChina Company
Limited/University of Petroleum (East China)
|
Family ID: |
4590277 |
Appl. No.: |
10/004119 |
Filed: |
November 2, 2001 |
Current U.S.
Class: |
208/108 |
Current CPC
Class: |
C10G 47/26 20130101;
C10G 65/12 20130101 |
Class at
Publication: |
208/108 |
International
Class: |
C10G 047/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 2, 2000 |
CN |
00123992.9 |
Claims
What is claimed is:
1. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure, comprising the
steps of: a fully mixed and heated slurry coming into a
hydrocracking reactor from the bottom while effluent out of the top
of said reactor enters a high-temperature and high-pressure
separation system whereby the effluent is separated; material flow
in vapor phase coming into an online fixed-bed hydrotreating
reactor while material flow in fluid phase enters a low-pressure
separation system.; the material flow in fluid phase of the
low-pressure separation system coming also into the online
fixed-bed hydrotreating reactor; then the material flow
hydrogenated and treated through the fixed-bed coming into the
conventional separation system for separation to obtain products;
and vacuum gas oil fractionated out of the vacuum distillation
tower returning partially to slurry-bed hydrocracking reactor to be
treated.
2. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein said high-pressure separation system includes a hot
high-pressure separator and a cold high-pressure separator
3. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein said low-pressure separation system includes a flash
drum, a vacuum distillation tower, a low-pressure separator, and a
cold low-pressure separator.
4. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein said conventional separation system includes a vacuum
distillation tower.
5. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein said fixed-bed hydrotreating reactor lies on line in all
process and hydrogen source comes from hot material flow of the
hydrocracking reactor of the suspension bed.
6. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein the online mixer for mixing raw materials and catalyst
is applied.
7. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
6, wherein the online mixer for mixing raw materials and catalyst
is a shear pump or a static mixer.
8. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
7, wherein said shear pump is a shear pump with 2-7 levels.
9. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein a part of the vacuum gas oil fractionated out of the
vacuum distillation tower in the low-pressure separation system
returns to said slurry-bed hydrocracking reactor; the other part
returns to said slurry-bed hydrocracking reactor together with the
slurry to enhance the yield of diesel oil.
10. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein said hydrocracking reactor is a total feedback mixed
reactor, the slurry containing untreated residual oil, liquid
catalyst, recycled bottoms, recycled vacuum gas oil and fresh
hydrogen in the reactor are cycled continuously from a circulating
pump to maintain a total feedback mixed state.
11. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein the reaction conditions of said hydrocracking reactor
are: reaction pressure: 8- 12 Mpa, reaction temperature:
420-460.degree. C., total volume hourly space velocity: 0.8 -1.4,
recycling ratio of bottom oil/fresh raw materials: 0.3-0.8, dosage
of catalyst based on metal: 50-2000 ppm, ratio of hydrogen to fresh
raw materials: 800-1000; and the conditions of the online fixed-bed
hydrotreating reactor are: reaction temperature: 300- 400.degree.
C., reaction pressure: a little less than the pressure of the
slurry-bed hydrocracking reactor, volume hourly space velocity:
1.0-2.0, and, ratio of hydrogen/oil: 300-1000.
12. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, wherein the catalyst used by the hydrocracking reactor of
suspension bed is a highly dispersed multimetallic liquid catalyst
mainly comprising multimetallic salts.
13. A heavy oil hydrocracking process with multimetallic liquid
catalyst in suspension bed under normal pressure according to claim
1, comprising the steps of a fully mixed and heated slurry coming
into a hydrocracking reactor from the bottom of a slurry-bed while
effluent out of the top of said reactor enters a high-temperature
and high-pressure separation system whereby the effluent is
separated; material flow in vapor phase coming into an online
fixed-bed hydrotreating reactor while material flow in fluid phase
enters a low-pressure separation system; the material flow in fluid
phase of the low-pressure separation system coming also into the
online fixed-bed hydrotreating reactor, then the material flow
hydrogenated and treated through the fixed-bed coming into the
conventional separation system for separation to obtain products,
wherein the reaction conditions of said hydrocracking reactor are:
reaction pressure: 8-12 Mpa, reaction temperature: 420-460.degree.
C., total volume hourly space velocity: 0.8-1.4, recycling ratio of
bottom oil/fresh raw materials: 0.3-0.8, dosage of catalyst based
on metal: 50-2000 ppm, ratio of hydrogen to fresh raw materials:
600-1000; and the conditions of the online fixed-bed hydrotreating
reactor are: reaction temperature: 300-400.degree. C., reaction
pressure: a little less than the pressure of the slurry-bed
hydrocracking reactor, volume hourly space velocity: 1.0-2.0, and,
ratio of hydrogen/oil: 300-1000.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a new heavy oil hydrocracking
process using a multimetallic liquid catalyst in a slurry-bed,
particularly an improvement of lightweight treatment of heavy oil
in the petroleum processing technology. According to the present
invention, a slurry-bed hydrocracking reactor and the highly
dispersed multimetallic liquid catalyst are mainly applied during
the process. A fixed-bed hydrotreating reactor is also used on line
to enhance lightweight oil yield from heavy oil under normal
pressure.
BACKGROUND OF THE INVENTION
[0002] In today's world, research on slurry-bed hydrocracking
processes are very active. There are now more than ten such
technologies that are in pilot test stage. Some of them have
already had industrialized application. But, in these technologies,
there exist numerous limitations and shortcomings. The following
are some examples.
[0003] One example is the VEBA-Combi-Cracking (VCC) process
developed in Germany. This process adopts red mud, i.e., a kind of
solid material with iron content, and the fine coke powder of Bovey
coal as a catalyst. In this technology, not only is the reaction
pressure (30-75 Mpa) relatively high, but also a relatively large
amount of catalyst, such as about 5% weight percent of raw
materials, must be used.
[0004] A second example is the Micro-Cat technology developed by
ExxonMobil. In this technology, phospho-molybdic acid and
molybdenum naphthenate are used as catalyst. Although the
dispersion rate and activity of the catalyst are high, this
technology remains for now in an experimental scale (1 drum/day). A
reason may be that the cost of catalyst is relatively high with low
economic profit.
[0005] A third example is the HDH technology developed by the
Venezuelan INTEVEP Company. This technology uses as a catalyst a
kind of inexpensive natural ore that is a special local product
currently in Venezuela after it is crushed and fined. Although the
catalyst is inexpensive, it must be used in a very large amount
(2-3 m %). The required separation system for solid matter of
catalyst and non-converted bottom oil is relatively complex.
Furthermore, the mineral ore is produced specially only in
Venezuela.
[0006] Still another example is the Canadian CANMET process. The
catalyst used in this process is FeSO.sub.4.H.sub.2O with a
relatively high dosage (1-5%). The desulfuration and
denitrogenation rate of this process is not high, although it does
appear to achieve the expected quality of products. There also
exist some problems in the separation of catalyst and non-converted
bottom oil.
[0007] A fifth example is the SOC technology developed by a
Japanese company, Ashi Kasei Industrial Co. In this technology, the
catalyst, consisting of highly dispersed superfine powder and
transition metallic compound, is used with high reaction activity
and good anticoking effects. But, this process requires a high
reaction pressure (20-22 Mpa) and a relatively high investment cost
in the facility.
[0008] There are other technologies currently available around the
world, such as the Aurabon technology developed by the American UOP
Company, the HC3 technology developed by Canada, etc. But, some of
these technologies are only being tested on an experimental scale,
some use too great a dosage of catalyst, some adopt a solid
catalyst, and some use expensive catalysts or require high reaction
pressures. In these prior processes, the catalyst used is a single
catalyst or a mixture of catalysts. Most of the raw materials being
processed using the above-discussed technologies were high
sulfur-containing heavy oil. The applications of these prior
technologies were also limited in processing low sulfur-containing
heavy oil.
SUMMARY OF THE INVENTION
[0009] In order to avoid the shortcomings of the prior processes,
the object of the present invention is to provide a new and
improved heavy oil hydrocracking process using a multimetallic
liquid catalyst in the slurry-bed.
[0010] In order to carry out the aims of this invention, the
technical embodiment of this invention can be realized through the
following methods:
[0011] According to the present invention, a heavy oil
hydrocracking process using a multimetallic liquid catalyst in a
slurry-bed reactor under normal (atmospheric) pressure is provided.
A slurry-bed hydrocracking reactor charged with a multimetallic
liquid catalyst and an online fixed-bed hydrotreating reactor are
installed. An online mixer is used to make full mixture of feed oil
with catalyst, followed by low-temperature sulfidation. The
effluent out of the reactors is separated under a high-pressure or
low-pressure separating system or using a conventional separating
system. Vacuum gas oil is separated and recycled.
[0012] Particularly, the present invention provides a heavy oil
hydrocracking process using multimetallic liquid catalyst in the
slurry-bed reactor under normal pressure conditions. The feeds,
namely heavy oil mixed with catalyst and hydrogen, come into the
bottom of a slurry bed hydrocracking reactor. The effluent out of
the top of the reactor enters a high-temperature and high-pressure
separation system whereby the effluent is separated into vapor flow
and liquid flow. Vapor flow enters an online fixed-bed
hydrotreating reactor, while liquid flow enters a low-pressure
separation system. The vapor flow out of the top of the
low-pressure separation system is also directed into the online
fixed bed hydrotreating reactor after being cooled. The effluent
out of the fixed bed hydrotreating reactor is fed into a
conventional separation system, such as vacuum distillation
tower.
[0013] The high-pressure separation system of the present invention
preferably includes a hot high-pressure separator and a cold
high-pressure separator. The low-pressure separation system used in
the present invention preferably includes a flash drum, a vacuum
distillation tower, a low-pressure separator, and a cold
low-pressure separator
[0014] The vacuum gas oil fractionated out of the vacuum
distillation tower is returned, at least partially, to a slurry-bed
hydrocracking reactor for further treatment.
[0015] The fixed-bed hydrotreating reactor is on line in the
process of this invention. The hydrogen source comes from hot
material flow of the slurry-bed hydrocracking reactor. The online
mixer for mixing raw materials and catalyst is preferably a shear
pump or a static mixer. In a particularly preferred embodiment, the
shear pump is a shear pump with 2-7 levels.
[0016] A first portion of the vacuum gas oil fractionated out of
the vacuum distillation tower in the low-pressure separation system
is returned to the slurry-bed hydrocracking reactor. The other
portion is returned to the slurry-bed hydrocracking reactor
together with the slurry to enhance the yield of diesel oil.
[0017] According to the present invention, the hydrocracking
reactor is a total feedback mixed reactor, and the slurry in the
reactor is cycled continuously from a circulating pump to maintain
a total feedback mixed state. The slurry typically comprises
untreated residual oil, liquid catalyst, recycled bottoms, recycled
vacuum gas oil and fresh hydrogen.
[0018] In carrying out the process of the present invention, the
preferred reaction conditions of the slurry-bed hydrocracking
reactor are about as follows:
[0019] reaction pressure: 8-12 Mpa,
[0020] reaction temperature: 420-460.degree. C.,
[0021] total volume hourly space velocity: 0.8 -1.4 h.sup.-1,
[0022] recycling ratio of bottom oil/fresh raw materials:
0.3-0.8,
[0023] dosage of catalyst based on metal: 50-2000 ppm,
[0024] ratio of hydrogen to fresh raw materials: 600-1000.
[0025] The preferred conditions of the online fixed-bed
hydrotreating reactor are about as follows:
[0026] reaction temperature: 300-400.degree. C.,
[0027] reaction pressure : a little less than the pressure of the
hydrocracking reactor of suspension bed,
[0028] volume hourly space velocity: 1.0-2.0 h.sup.-1, and,
[0029] ratio of hydrogen/oil: 300-1000.
[0030] In other words, the process of the present invention
includes many technical innovations to provide a completely new and
improved slurry-bed hydrocracking technology. The present invention
uses a highly dispersed multimetallic liquid catalyst in a
slurry-bed hydrocracking reactor, and it adopts on line a fixed-bed
hydrotreating reactor so that the technology can solve persistent
problems of processing residual oil including low sulfur petroleum
as well as high sulfur petroleum. The process of this invention is
especially effective to process at normal pressures residual oil
having relatively high content of nitrogen and/or metal, a
relatively high viscosity, a high acid number and/or a high
residual coke content. The process of this invention is further
characterized in adopting a slurry-bed hydrocracking reactor
charged with multimetallic liquid catalyst and an online fixed-bed
hydrotreating reactor. The process of this invention also uses an
online mixer to effect thorough mixing and low-temperature
sulfuration of the raw materials and catalyst The process of this
invention is further characterized in adopting a high and
low-pressure separation system and a conventional separation system
for treating the effluent out of the reactor. The process of this
invention also adopts the recycle technology for processing the
vacuum gas oil. In the present process, the fully mixed and heated
slurry is flowed into the bottom of a slurry-bed hydrocracking
reactor, while the effluent flowing out of the top of the reactor
is fed to a high-temperature and high-pressure separation system,
where the effluent is separated after it enters the hot
high-pressure separation reactor. The material flow in the vapor
phase is fed into an online fixed-bed hydrotreating reactor, while
the material flow in the liquid phase is fed to a low-pressure
separation system. The material flow in liquid phase coming from
the low-pressure separation system (excluding the bottom oil) is
also fed into the online fixed-bed hydrotreating reactor. Then, the
material flow, after being hydrogenated and treated through the
fixed bed, is fed to the conventional separation system for
separating into a variety of products. The high-pressure separation
system preferably includes a hot high-pressure separator and a cold
high-pressure separator. The low-pressure separation system
preferably includes a flash drum, a vacuum distillation tower, a
low-pressure separator, and a cold low-pressure separator. The
conventional separation system preferably includes a vacuum
distillation tower. The vacuum gas oil fractionated out of the
vacuum distillation tower is at least partially returned to the
slurry-bed hydrocracking reactor for further treatment.
[0031] In order to achieve the above-mentioned aims, the process of
this invention was designed such that the fixed-bed hydrotreating
reactor would be used throughout the processing. The preferred used
hydrogen source for the present invention comes from hot material
flow of the slurry-bed hydrocracking reactor. The mixer for mixing
raw materials and catalyst is preferably a multistage shear pump or
a static mixer. The multistage shear pump may advantageously be a
shear pump with 2-7 levels. A first part of the vacuum gas oil
fractionated out of the vacuum distillation tower in the
low-pressure separation system is preferably returned to the
slurry-bed hydrocracking reactor. The other part preferably is
returned to the slurry-bed hydrocracking reactor together with the
fresh feed. The slurry in the slurry reactor is recycled
continuously from a recirculating pump to maintain a total feedback
mixed state. The slurry may typically contain untreated residual
oil, liquid catalyst, recycled bottoms, recycled vacuum gas oil and
fresh hydrogen.
[0032] In the present invention, the reaction conditions of the
slurry-bed hydrocracking reactor are preferably as follows: the
reaction pressure is about 8-12 Mpa; the reaction temperature
ranges from about 420-460.degree. C.; the total volume hourly space
velocity is about 0.8-1.4 h.sup.-1; the recycling ratio of bottom
oil over fresh feed oil is about 0.3-0.8; the dosage of catalyst
used relative to total weight of metal is about 50-2000 ppm; and
the ratio of hydrogen to fresh feed oil is about 600-1000. The
conditions of the online fixed-bed hydrocracking reactor are
preferably as follows: the reaction temperature is about
300-400.degree. C.; the pressure is preferably just a little below
the pressure of the slurry-bed hydrocracking reactor; the volume
hourly space velocity is about 1.0-2.0 h.sup.-1; and the ratio of
hydrogen over feed oil is about 300-1000. The catalyst used by the
slurry-bed hydrocracking reactor is preferably a highly dispersed
multimetallic liquid catalyst. The principal components of the
multimetallic liquid catalysts according to the present invention
are the multimetallic salts. The catalyst used in the fixed-bed
hydrotreating reactor may be catalyst 3936 or RN-2 hydrocracking
catalyst, or similar catalysts as are commonly used in the
industry.
[0033] There are numerous differences between the hydrocracking
technology of the present invention and the several hydrocracking
technologies of the prior art processes. Some of those key
differences include the following:
[0034] (1) The slurry-bed hydrocracking reactor in the present
invention applies highly dispersed (micron or nm) multimetallic
liquid catalyst. The effective metal components of the catalyst
include nickel, iron, molybdenum, manganese, cobalt and the like.
Because a major part of the metal components of the catalyst is
recovered from the industrial waste materials, the cost is thereby
greatly reduced. The multimetallic liquid catalysts of the present
invention differ fundamentally from the solid powder catalysts or
the dispersed catalysts with small amounts of other components
which are commonly used in the world.
[0035] (2) Another feature of the present invention is the adoption
of a novel catalyst dispersion and low-temperature sulfuration
technology. In the present invention, a 2-4 level shear pump is
preferably used in the flow pipeline for raw oil and catalyst which
are thereby dispersed and mixed at about 2000-5000 turns/m.
Thereafter, the sulfuration of catalyst in the mixed materials is
completed using gas containing hydrogen sulfide at the temperature
of about 100-180.degree. C.
[0036] (3) In still another difference from the prior processes,
the present invention adopts a circulating cracking route with
vacuum gas oil and bottom oil. The main products of the process are
naphtha and diesel oil as well as a small amount of bottom oil.
[0037] (4) As the present invention adopts a total return mixed
cracking reactor, only a relatively small amount of coke formation
results. The temperature of the reactor is very even and easy to
control so that it simplifies the reactor operation and temperature
control. Additionally, this invention adopts a high-temperature,
high-pressure online hydrotreating reactor that not only
efficiently makes full use of existing reaction temperature and
pressure, but also makes products of very high quality.
[0038] In comparison with the prior processes, the present
invention has the following additional advantages:
[0039] (1) The multimetallic liquid catalyst used in the process of
the present invention is highly dispersed resulting in surprisingly
improved performance. The particle size of the catalyst is small
(on the order of about 0.1-5 micron) with high activity, therefore
only a very small dosage (>0.1%) is needed. In addition, as many
metal components in the catalyst come from industrial waste
materials, the cost of this catalyst is very low.
[0040] (2) Due to the high activity of the multimetallic liquid
catalyst of the present invention, the reaction temperature is
relatively high (e.g., about 430-460.degree. C.) with a high
cracking conversion rate (80-90%) and with little coking formation
(<1%).
[0041] (3) Low reaction pressure can be used, (e.g., hydrogen
partial pressure of reaction of about 8-12.0 Mpa). The industrial
process is simple and, for example, only 1-2 reactors need to be
used in the process, thereby resulting in low capital costs for
construction of facilities to carry out the process of this
invention.
[0042] (4) As the present invention utilizes a total return mixed
cracking reactor in combination with a vacuum gas oil circulating
cracking and high-temperature, high-pressure online treating
reactor, it avoids the need to build more hydrotreating and vacuum
gas oil hydrocracking cracking facilities. It also results in
products of high quality. After separating the product into
components, the naphtha recovered can be used as reforming stock
and for cracking materials, and the diesel oil is sweet oil on
average having a hexadecane number with low-nitrogen content and of
high quality.
[0043] Because vacuum gas oil or bottom oil circulation is adopted
as a feature of this invention, it increases the flexibility of the
operation of the facility. The present process is preferably
applied to mainly produce naphtha and diesel oil. If necessary,
however, it can also be slightly modified to produce high quality
vacuum gas oil.
[0044] The process of the present invention can play a specific
role. It can realize a very high recovery rate. It has very
advantageous benefits in processing all kinds of heavy oils,
including those of low quality, as well as viscous crude, including
normal pressure residual oil and very viscous ones. It is
especially effective in processing petroleum residual oil with high
nitrogen content, high metal content, high viscosity, having a high
acid number and having high residual coke, still realizing
conversion rates of more than 80-95%. Thus, the process of this
invention truly has a wide-range of industrial applications.
DETAILED DESCRIPTION OF THE DRAWING
[0045] FIG. 1 shows a schematic process flow chart of the present
process, wherein the reference numerals in the appended drawing are
described as follows:
[0046] 1 indicates a hydrogen heating furnace.
[0047] 2 indicates an oil heating furnace.
[0048] 3 indicates a hot high-pressure separator.
[0049] 4 indicates a slurry-bed hydrocracking reactor.
[0050] 5 indicates a flash drum.
[0051] 6 indicates a vacuum distillation tower.
[0052] 7 indicates a separator.
[0053] 8 indicates a fixed-bed hydrotreating reactor.
[0054] 9 indicates a cold high-pressure separator.
[0055] 10 indicates a cold low-pressure separator.
[0056] 11 indicates an atmospheric vacuum distillation tower.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0057] In the actual operation of the present invention as
indicated in FIG. 1, a highly dispersed multimetallic catalyst (UPC
series) is used in a slurry-bed hydrocracking reactor. Catalyst No.
3936 or RN-2 hydrotreating catalyst is used in the hydrotreating
reactor having a fixed bed. A residual oil of raw materials
containing a highly dispersed multimetallic catalyst and a little
curing agent is mixed with vacuum gas oil or bottom oil and pumped
to the residual oil heating furnace 2. After being heated to about
380-480.degree. C., the residual oil is mixed again with the
hydrogen coming out of the hydrogen heating furnace 1 and having a
corresponding temperature. This first mixed stream is then fed into
the slurry-bed hydrocracking reactor 4. The effluent out of the
hydrocracking reactor 4 is flashed and distilled into gas and
liquid phases in a hot high-pressure separator 3. The material flow
in the gas phase, including mixed hydrogen, is fed online directly
into fixed-bed hydrotreating reactor 8 from the top of separator 3.
The liquid flow (i.e., black oil with catalyst) coming out of the
bottom of separator 3 is fed into a flash drum 5 to be flash
distilled after it is decompressed. The material flow out of the
top of the flash drum 5, together with the sidedraw material flow
out of vacuum distillation tower 6, and also together with the
material flow out of the bottom of separator 7, are joined with
each other to form a second mixed stream. At least a portion of
this second mixed stream may be sent to reactor 8 for
hydrotreating, or a portion may be remixed with the oil out of the
bottom of vacuum distillation tower 11 which is used as exit
equipment for processing vacuum gas oil. Alternatively, this second
mixed stream could also be mixed with the recycled bottoms, then
sent to the slurry bed hydrocracking reactor 4 via heating furnace
2. The liquid flow out of the bottom of the flash drum 5 is sent to
a vacuum distillation tower 6. A part of the bottom oil in the
bottoms stream from the vacuum distillation tower 6 is withdrawn
from the system while another part is recirculated as bottom oil.
The material flow out of the top of the vacuum distillation tower 6
is sent to a separator 7. The gas phase from the top of the
separator 7 is withdrawn from the system as end gas. The reaction
product and hydrogen coming from the fixed-bed online hydrotreating
reactor 8 is sent into a cold high-pressure separator 9 to effect
separation of oil, gas and water after being heat-exchanged and
cooled down and being water-flooded whereby ammonium salt is
generated after the dissolution step. Sulfur-containing wastewater
with dissolved NH.sub.3 and H.sub.2S is withdrawn from cold
high-pressure separator 9 and is sent together with the combination
of sulfur-containing wastewater coming from the cold low-pressure
separator 10 to be processed jointly. The flashed gas from the cold
high-pressure separator had a high content of hydrogen. Most of
that hydrogen is returned to the reaction system as recycled
hydrogen after being boosted in pressure by a recycled hydrogen
compressor and mixed with fresh hydrogen. In order to maintain the
needed concentration of recycled hydrogen to meet system
requirements, it may be necessary to blow off a small amount of gas
from the cold high-pressure separator as a waste hydrogen gas
stream. In order to minimize hydrogen loss, a membrane separator
may be used to recover some of the hydrogen from this waste
hydrogen stream. The end gas released by the membrane separator is
sent off to be desulfated. The oil flow through the cold
high-pressure separator 9 and cold low-pressure separator 10 is
sent to atmospheric vacuum distillation tower 11 after being heat
exchanged and heated. A mixed naphtha stream is then recovered from
the top of the vacuum distillation tower 11, a diesel oil product
is obtained as a sidedraw from tower 11, and bottom oil out of the
bottom of the vacuum distillation tower 11 is mixed with
decompressed vacuum gas oil taken as a sidedraw from vacuum
distillation tower 6 to form raw materials for the catalytic
cracking equipment.
EXAMPLE
[0058] In the following example, Karamay atmospheric residue was
used in connection with carrying out a hydrocracking process in
accordance with this invention. The reaction temperature of the
Karamay atmospheric residue in the 30-100 ton/year medium-size
facility was 400-480.degree. C. The hydrogen partial pressure was
4-12 Mpa. Multimetallic liquid catalyst Type UPC-21 was used. The
total volume hourly space velocity of raw materials was 1.0-1.3
h.sup.-1. The volume hourly space velocity of fresh raw materials
was 0.4-0.8 h.sup.-1. The yield of this slurry-bed hydrocracking
cracking process reaches up to 90-97 m % when carried out at
temperatures below 524.degree. C. The concrete data for this
process is as follows.
[0059] 1. Product distribution resulting from the suspension bed
hydrocracking cracking of atmospheric residue from Karamay Oil
field, China under different reaction temperatures (single pass
yield):
1 Reaction temperature, 430 435 440 445 450 .degree. C. hydrogen
partial 10.0 10.0 10.0 10.0 10.0 pressure, Mpa Hydrogen-oil ratio,
740/1 742/1 757/1 737/1 735/1 Mm.sup.3/m.sup.3 Total volume volume
1.13 1.13 1.10 1.13 1.14 hourly space velocity, h.sup.-1 Product
distribution, m % C1-C4 (gas) yield 4.63 4.70 4.76 4.96 5.03
C5-180.degree. C. (naphtha 6.67 7.97 9.27 10.28 11.68 fraction)
yield 180-350.degree. C. (diesel oil 19.02 22.56 24.08 27.41 30.55
fraction) yield 350-524.degree. C. (vacuum 39.89 39.51 37.50 37.62
35.00 gas oil fraction) yield <524.degree. C. yield 70.21 75.13
75.61 80.27 82.25 >524.degree. C. (bottom oil) 30.84 26.06 25.39
20.90 19.00 yield Hydrogen loss: m % 1.06 1.09 1.13 1.18 1.25 Total
yield: m % 101.6 101.19 101.0 101.18 101.25
[0060] 2. Product distribution resulting from the suspension bed
hydrocracking of atmospheric residue from Karamay Oil Field, China
under different reaction temperatures (single pass and circulating
yield):
2 Reaction temperature, .degree. C. 440 440 445 445 Hydrogen
partial pressure, Mpa 10.0 10.0 10.0 10.0 Hydrogen-oil ratio,
Mm.sup.3/m.sup.3 757/1 800/1 737/1 800/1 Recycling ratio (fresh raw
100 66/34 100 70/30 material/bottom oil) Total volume volume hourly
space 1.10 1.14 1.13 1.14 velocity, 1/h Volume volume hourly space
1.10 0.75 1.13 0.80 velocity of fresh raw material, h.sup.-1
Product distribution, m % C1-C4 (gas) yield 4.76 5.50 4.96 7.40
C5-180.degree. C. (naphtha fraction) 9.27 9.60 10.28 13.80 yield
180-350.degree. C. (diesel oil fraction) 24.08 27.30 27.41 29.60
yield 350-524.degree. C. (vacuum gas oil 37.50 53.10 37.62 45.40
fraction) yield <524.degree. C. yield 75.61 96.30 80.27 96.20
>524.degree. C. (bottom oil) yield 25.39 4.60 20.90 5.00
Hydrogen loss: m % 1.13 0.92 1.18 1.18 Total yield: m % 101.0
100.92 101.18 101.18
[0061] 3. Composition and characteristics of the naphtha fraction
(IBP-180.degree. C.) before and after refining
3 Before After After After After Refining condition refining
refining refining refining refining Fraction components of refining
-- IBP-350 IBP-350 IBP-350 IBP-500 raw materials, .degree. C.
Refining temperature, .degree. C. -- 360 380 400 400 Refining
pressure, Mpa -- 10.0 10.0 10.0 10.0 Composition of Hydrocarbon
family, m % Normal paraffin hydrocarbon 20.61 24.94 24.97 25.05
21.30 Isoalkane 32.81 38.04 38.95 39.62 36.50 Naphthene hydrocarbon
15.91 31.63 31.34 30.97 33.65 aromatic hydrocarbon 10.40 5.39 4.74
4.36 6.10 olefine hydrocarbon 20.27 0.0 0.0 0.0 0.0 Potential
content of aromatic -- 38.about.42 38.about.42 38.about.42
38.about.42 hydrocarbon, m % Octane value 78.1 73.4 73.9 74.3 75.0
Density (20.degree. C.), g/cm.sup.3 0.7543 0.7451 0.7454 0.7519
0.7499 Sulfur, .mu.g/g 440 0.5.about.1.0 0.5.about.1.0
0.2.about.0.6 0.5.about.1.0 Nitrogen, .mu.g/g 658 1.0.about.2.0
1.0.about.2.0 0.5.about.1.5 1.0.about.2.0 Basic nitrogen, .mu.g/g
160 <1.0 <1.0 <1.0 <1.0
[0062] 4. Composition and characteristics of the diesel oil
fraction (180-350.degree. C.) before and after refining
4 Before After After After After Item refining refining refining
refining refining Fraction components of refining -- IBP-350
IBP-350 IBP-350 IBP-500 raw materials, .degree. C. Refining
temperature, .degree. C. -- 360.quadrature. 380.quadrature.
400.quadrature. 400.quadrature. Refining pressure, Mpa -- 10.0 10.0
10.0 10.0 Density (20.degree. C.), g/cm.sup.3 0.8464 0.8303 0.8241
0.8202 0.8449 Viscosity (20.degree. C.), mm.sup.2/s 8.79 3.83 3.47
3.40 3.97 Viscosity (40.degree. C.), mm.sup.2/s 3.16 2.70 2.33 2.18
2.58 Sulfur, .mu.g/g 570 18.2 13.5 12.4 19.3 Nitrogen, .mu.g/g 1510
5.5 4.3 4.1 8.9 Basic nitrogen, .mu.g/g 780 5.0 3.9 3.6 5.9 Aniline
point, .degree. C. 62.2 72.0 72.0 70.1 67.9 Centane value 49.6 58.1
60.3 62.2 53.1 Acidity, mg KOH/100 ml 35.62 3.40 2.41 2.14 3.45
Solidifying point, .degree. C. -38 -37 -37 -32 -37 Cold filtering
point, .degree. C. <-20 <-20 <-20 <-20 <-20
[0063] While the invention has been described in connection with a
preferred and several alternative embodiments, it will be
understood that there is no intention to thereby limit the
invention. On the contrary, it is intended that this invention
cover all alternatives, modifications and equivalents as may be
reasonably included within the spirit and scope of the invention as
defined by the appended claims, which are the sole definition of
the invention.
* * * * *